|
KMID : 0376219800170010113
|
|
Chonnam Medical Journal
1980 Volume.17 No. 1 p.113 ~ p.120
|
|
|
Studies on Neurohumoral Transmitter in the Vein -Characterization of a-Adrenoceptors
|
|
|
|
|
Abstract
|
|
|
1. Minute doses of clonidine and norepinephrine(NE) inhibited contractile responses of the rabbit and dog isolated portal vein to field stimulation and the inhibition was antagonized by yohimbine.
2. Contractile responses of the rabbit and dog isolated portal vein to low frequency(5, 10Hz) stimulation were markedly inhibited by clonidine and NE.
3. In the rabbit isolated portal vein, the contraction due to clonidine(0.03, 0.1 μg/me) and NE were inhibited by yohimbine but the contractions due to phenylephrine(PE) and clonidine(0.3pg/n€) were not affected by yohimbine. The contractions due to PE, NE and clonidine(0.1, 0.3μg/me) except clonidine (0.03μg/EE) were inhibited by thymoxamine.
4. In the rat isolated portal vein, the contractions due to clonidine,. NE and PE were markedly inhibited by both yohimbine and thymoxamine.
5. The above results indicate that (1) NE released from nerve endings in the rabbit and dog isolated portal vein by field stimulation contracted the portal vein itself and also inhibited further NE-release by acting as antagonist on the presynaptic a-receptor, ⓒ postjunctional a-receptor in the smooth muscle of the rabbit isolated portal vein can be subdivided into a typical postsynaptic a-receptor and an a-receptor similar to a presynaptic a receptor in character.
|
|
|
KEYWORD
|
|
|
|
|
|
FullTexts / Linksout information
|
|
|
|
|
|
Listed journal information
|
|
|
|
|